It has been a routine practice to insert a catheter through a puncture site into a blood vessel to either treat a diseased blood vessel by a procedure known in the art as percutaneous transluminal angioplasty (PTA), or to deliver systemic drugs to the blood stream for chemotherapeutic applications. In the case of a PTA procedure, an introducer sheath is inserted into an artery through the puncture site such that a balloon or other type of catheter can then be inserted into the vessel to carry out the procedure within the vessel. Depending upon the nature of the disease and the site of arterial insertion, the size of an introducer sheath can vary from about 1 mm to as large as about 5 mm. One of the complications of these procedures is hemorrhaging at the percutaneous puncture site after removal of the catheter and the introducer sheath. In order to stop the bleeding, pressure is applied at the puncture site until hemostasis occurs. Since the angioplasty procedures often require the use of anticoagulant, the pressure approach is not always effective and may require a long period of pressurization.
A variety of commercial hemostatic products are available such as those disclosed in U.S. Pat. Nos. 2,465,357; 3,742,955; and 3,364,200. A felt or fleece like collagen hemostat is disclosed in U.S. Pat. No. 4,066,083. A hemostatic collagen paste comprising a mixture of collagen powder and saline is disclosed in U.S. Pat. No. 4,891,359. A number of other collagen based hemostatic materials are disclosed in U.S. Pat. Nos. 4,412,947; 4,578,067; 4,515,637; 4,271,070; 4,891,359; 4,066,083; 4,016,877 and 4,215,200. None of these patents teach the art of hemostasis at a vessel puncture site.
A device to close an arterial puncture site of a blood vessel is disclosed in U.S. Pat. No. 4,744,364 to Kensey. This device involves the insertion of an expandable, resorbable material inside of the lumen of a blood vessel via a tubular member which fits inside an introducer sheath. A retraction filament is secured to the resorbable material for pulling it to the puncture site so that the resorbable material engages the inner surface of the blood vessel contiguous with the puncture. The filament is held taut and taped or otherwise secured to patients, skin to hold the resorbable material in position.
The Kensey device introduces several potential risks to the patient. The device may induce an acute thrombosis due to imperfect alignment of the sealing material or to non-hemocompatibility of the material. The premature degradation of the filament may leave the sealing material unsecured, leading to embolization distal to the puncture site. The migration of the sealing material may not only cause rebleeding, but potential thrombosis which requires surgical intervention. The potential risks involved in such a device may outweigh the benefits such a device can offer. Thus, a safe and effective method to close a puncture site and stop the bleeding is still highly desirable and welcome.
Accordingly, it is the primary object of the present invention to provide an implant which will close a puncture site and stop the bleeding while substantially reducing the disadvantages and risks associated with the prior art.
It is a further object of the present invention to provide an implant which self-expands in vivo to fill the voids or defects of a tissue or organ with a biocompatible, resorbable material.
It is still a further object of the present invention to provide a method to deliver the biocompatible, resorbable implant material to tissues or organs of interest by a tubular delivery device.
It is another object of the present invention to provide a means to deliver medicaments, antibiotics, growth factors and other biologically active molecules to selected tissues or organs.
It is yet another object of the present invention to provide a method of manufacturing the implant.